Because documentation lives away from the work. Updating it is a separate task nobody is measured on, so it describes the project as it was imagined rather than as it is.
Docs are written pages attached to a project or phase: scope, decisions, runbooks and reference, versioned in place.
Pages attach to the project and keep their history. A page can be linked from a task, so the person doing the work reaches the reference from the work rather than searching for it.
Somebody asks why the schema was designed a particular way. The decision page is on the project, with the date and the alternatives that were rejected, next to the tasks that implemented it.
It will not keep itself current. Loop can show a page has not changed in six months against a project that has; deciding whether that matters is a person's job.
Docs link to tasks and deliverables, and can be exposed to a client through the portal individually.
Yes, per page, with who changed what.
Yes, individually, through the portal.
Yes, and a project template can bring its doc set with it.
Fourteen days, every module, no card. Or half an hour with someone who will run it on your own records and tell you where it does not help.